Ontogenesis of haemocytes in shrimp (Fenneropenaeus chinensis) studied with probes of monoclonal antibody

Monoclonal antibodies (Mabs) specifically against haemocytes of shrimp (Fenneropenaeus chinensis) were employed to study the ontogenesis of haemocytes by immunofluorescence assay technique (IFAT) with the aids of avidin–biotin complex method. Different developmental stages were identified by means of histochemical staining. Stages including blastula, gastrula, limb bud stage, embryonic-nauplius and nauplius were examined. With Mab 2A3 against both hyline, semi-granular and granular haemocytes, the first positive cells were detected at the limb bud stage of the embryos. Distinguishable positive haemocytes with a diameter of about 7 μm appeared in embryonic-nauplius. Whereas, with Mab 1H11 specific to cytoplasmic granulars in haemocytes, the first positive granular haemocytes were observed at the stage of embryonic-nauplius. Increased number of both total and granular haemocytes at the stage of nauplius impressed a possible enhancement of the immune system as the embryogenesis progressed.